David Lyn Jenkins (30 April 1927 – 4 August 2012), known professionally as David Lyn, was a Welsh television, film and stage actor and director who in his 40 year career was at the forefront in the development of professional Welsh language theatre in Wales in the 1960s and 70s and won a BAFTA Cymru.

David Lyn Jenkins was born on 30 April 1927 in Porth, Rhondda Cynon Taf, one of three children and the only son of Violet Margaret née Evans (1904–1992) and David Jenkins (1896–), Theirs was an English-speaking family, although the children picked up the rudiments of the Welsh language. Lyn was raised on a smallholding in Cynwyl Elfed in Carmarthenshire, an area steeped in poverty, and his own early family life was one of struggle; after winning a place at the local grammar school he went on to attend the teacher-training course at Trinity College, Carmarthen. He later joined a weekend drama course where a tutor from the Royal Academy of Music (RAM) recognised his dramatic gifts and persuaded him to move to London to study. Lyn spent two years at the RAM and decided to take a career as an actor, making his début in experimental theatre clubs such as the Watergate Theatre, where the actors would on occasion improvise and where directors were not afraid to take risks.

In 1964 Lyn acted in The Wars of the Roses, the Royal Shakespeare Company's production of Shakespeare's Henry VI trilogy (1 Henry VI, 2 Henry VI, 3 Henry VI) and Richard III - the four plays having been conflated into a trilogy. The production was filmed by the BBC and shown on television in 1965. Also in the RSC's 1964 season Lyn appeared in Edward IV, Richard II, played the Earl of Cambridge in Henry V and the Doctor in Henry IV, Part 1 and Henry IV, Part 2.

Lyn took the step of leaving London to try his hand at acting in his native Wales. Throughout this period alongside his acting Lyn also developed a side-line in renovating houses and when he moved his family to North Wales he bought five derelict cottages and knocked them through into one long house, fitting a large church window in the front of the last cottage giving the building the appearance of an old chapel. In 1965 Lyn toured Ireland in a production of Pinter's The Caretaker with the Welsh Theatre Company. In 1966 he joined Cwmni Theatr Cymru, the Welsh-language wing of the Welsh Theatre Company, in the Absurdist Saer Doliau (Doll Mender or Doll Doctor), a play by the Welsh playwright Gwenlyn Parry. In 1972 Lyn purchased a 55 ft 50 ton Norwegian trawler, the Tolga, which he intended to renovate to fulfil a promise to his father to take him up the Zambezi. He and his family worked on making the trawler seaworthy.

As a boy Lyn had gained only a smattering of the Welsh language, and during this period he worked hard at the script to get his Welsh up to the standard necessary for him to be able to deliver the long speeches fluently. In this he was supported by his fellow cast members who made allowances for him at rehearsals. Over the ensuing years Lyn improved his knowledge of Welsh to such an extent that eventually he was able to act in and direct plays for Cwmni Theatr Cymru fluently in that language; among the plays he directed were: Pethe Brau (1972), a Welsh language version of The Glass Menagerie by Tennessee Williams; Esther by Saunders Lewis (1973) and Y Twr (1978) by Gwenlyn Parry.

Lyn became both impatient with the attitude of some of the older members of the drama committee of the Welsh Arts Council who expressed the hope that internationally acclaimed Welsh actors might be persuaded to return to perform in Wales, as well with the Welsh Theatre Company which produced plays with English actors and Welsh actors who lived and mainly worked in England but who acted in Wales only when they couldn't find work in England.

To promote a professionalism in Welsh theatre Lyn founded a Welsh Actors' Society, of which he wrote in 1977, "Whenever it spoke it almost frightened itself to death. It eventually made itself articulate on some important union matters after it had converted itself into the Welsh Committee of Equity. On theatre policy it was quite without courage." In the 1960s he was at the forefront of a group of Welsh actors who worked towards founding a National Theatre in Wales. Lyn almost succeeded in this aim when in 1966 he was among those who founded Theatr yr Ymylon, a bilingual touring theatre company based in Bangor which it was intended would grow into a national theatre for Wales. Lyn was the artistic director but the company folded in 1978 as the result of in-fighting over what constituted a "national theatre". Lyn returned to acting in television, most notably playing Joseph Parry in Off to Philadelphia in the Morning (1978) for the BBC.

By now disillusioned with the theatre scene in Wales he and his family sailed their trawler the Tolga from Barry to St Katharine Docks by Tower Bridge. Lyn turned his back on acting, preferring to work in London as a taxi driver while his wife Sally worked as a picture editor on Newsnight, with the couple living on the boat in the wheel house. In 1982 with the advent of S4C the two returned to Wales where Lyn learned how to direct for television and film. The Tolga sank in a dock in Wapping and later was raised and taken to a dock on the Thames where eventually she was scuttled. In 1984 Lyn founded Penadur, his television and film company.